repeatedletter

Repeatedletter is a linguistic and typographic phenomenon in which the same letter appears more than once in a row within a word or sequence. The most common instance is a double letter, such as “letter” with tt or “balloon” with ll and oo.

Orthography and etymology: In many languages, double letters reflect historical processes such as consonant gemination or vowel length, and they can be phonemic or orthographic. In English, double consonants often arise from morphological changes or borrowings and are usually preserved in spelling, though they do not always indicate a longer consonant. Double vowels, as in oo or ea, may indicate a historical vowel length or simply conventional spelling.

Cross-linguistic usage: In languages such as Italian, Finnish, and in Romanized forms of some scripts, doubled letters can indicate gemination or length and may affect pronunciation. Some languages use repeated letters for emphasis or to mark grammatical or semantic distinctions.

In computing and typography: Repeated letters can affect text processing, spelling correction, and search. Normalization and case-folding in Unicode may treat repeated letters differently, and stylized writing or informal text often elongates vowels or consonants for effect (sooo).

See also: gemination, reduplication, double consonant, orthography.